Solid soap composition



July 4, 1961 M. L. SHEELY ET AL 2,991,253

SOLID SOAP COMPOSITION Filed Aug. 20, 1952 2 Sheets-Sheet 1 TALLOW FATTY ACIDS j SYNTHETIC DETERGENT KOH I ADDITIVES I I I I I [:3:::::; IFIZZT4F:J STEAM I CRUTC ZHER |l E- FRAMES SLABBING AN 0 CUTTING DRYING PRESSING WRAPPING IN V EN TORS July 4, 1961 M. L. SHEELY ETAL 2,991,253

SOLID soAP COMPOSITION Filed Aug. 20, 1952 KOH i 2 Sheets-Sheet 2 TA LLOW FATTY ACIDS SQUEEZE ROLLERS EXTRUSION DIE CUTTING PRESSING I I INVENTORS:

WRAPPING MGM 6 61% ATTORNEY United States Patent Office I V 2,991,253 SOLID SOAP COMPOSITION Madison L. Sheely, Western Springs, and Emmett P. Glynn, Chicago, 111., assignors to Armour and Compauy, Chicago, 111., a corporation of Delaware Filed Aug. 20, 1952, Ser. No. 305,418 9 Claims. (Cl. 252-121) This invention relates to solid soap composition.

More particularly, this invention relates to a solid soap composition characterized by its detergent power in hard and salt water. The solid soap composition of this invention has particular utility when formed into bars, but can also be employed in the form of chips, granules, etc.

Soap can be defined as a salt of one or more of the higher fatty acids with an alkali or metal. Most soaps are made by the action of sodium or potassium hydroxide on fats and oils, or fatty acids. The potassium and sodium soaps are commonly referred to respectively as potash and soda soaps. When soaps are prepared directly from the raw oils or fats by the use of potassium or sodium hydroxide the reaction is referred to as saponification, since it involves the splitting of the triglycerides of the fatty acids to form glycerine and the alkali metal salts of the fatty acids found in the Particular oil or fat. Soap can also be made by a neutralization reaction between sodium or potassium hydroxide and free fatty acids, which are obtained from the fats or oils by various processes. Therefore, for purpose of convenience, soaps composed of potassium salts of the fatty acids will be referred to hereinafter as potassium soaps, while soaps composed of sodium salts of fatty acids will be referred to as sodium soaps. It will therefore be apparent that both sodium and potassium soaps can be prepared by saponification or neutralization reactions, depending on whether the starting material contains the triglycerides or the free fatty acids.

The use of soaps in water containing dissolved inorganic salts presents problems because of the ionic nature of soap. Magnesium and calcium salts are particularly troublesome. It is these salts which are mainly present in so-called hard water. Salt water can be considered as an extreme type of hard water. In addition to calcium and magnesium salts, salt water also contains large quantities of sodium chloride and sodium sulfate. Among the particular difficulties arising when it is attempted to use soaps in hard or salt water, can be listed the followmg:

( 1) Getting the soap into solution;

(2) Having to dissolve a relatively large amount of the soap before the detergent action becomes effective; and

(3) Requiring excessive mechanical action to work up a lather and promote detergency.

Soaps which were particularly adapted for use in hard or salt water have heretofore been known. One type of these soaps has consisted of substantially pure sodium coconut oil soap. Coconut oil contains mainly carbon atoms. It has been found that sodium soaps of lauric and myristic acids tend to overcome the problems associated with the use of soaps in hard or salt water. In fact, it has been believed essential heretofore that soaps for use in hard or saltwater contain a large amount of lauryl and myristyl base soaps.

Coconut oil is the primary source of lauric and myristic acids for use in soap making. Coconut oil is relatively expensive, and it must be imported into the United States. Although the composition of the fatty acids of coconut oil varies somewhat, an approximate typical composition 'might be 48% lauric, 18% myristic, 8% caprylic, 7%

capric, 9% palmitic, 2% stearic, 6% oleic and 2% linolatented July 4, 1961 leic. Palm-kernel oil and Babassu-nut oil afe s'imilarin composition to coconut oil, but these oils must also be imported and are even more expensive than coconut oil.

Domestic fats and oils which are suitable for use in preparing soap contain mainly triglycerides of fatty acids having 1 6 or 18 carbon atoms. Inedible tallow, which is the main domestic raw material for preparing soap usually yields fatty acids in approximately the following proportions: 29% palmitic, 19% stearic, 46% oleic, 3% myristic and 3% linoleic. Other domestic oils which can be used in soap making have similar compositions. For example, soybean oil provides approximately 5% stearic acid, 7% palmitic acid, 33% oleic acid, and 55% linoleic acid. Cottonseed oil provides approximately 2% stearic acid, 21% palmitic acid, 33% oleic acid, and and 44% linoleic acid.

It is therefore a general object of this invention to provide a solid soap composition which is efiective in hard and salt water even though it does not contain any salts of fatty acids containing either 12 or 14 carbon atoms. More specifically, it is an object of this invention to prepare a solid soap composition in which the soap base is composed substantially exclusively of salts of fatty acids containing 16 and 18 carbon atoms. It is a further object of this invention to prepare a solid soap composition which is effective in hard or' salt water in which the soap base is composed exclusively of tallow soap. Another object of this invention is to prepare a solid soap composition of the characteristics and properties set out which is suitable for forming into bars. A still further object is to provide a solid soap composition in bar form containing soap in admixture with a synthetic detergent, which composition is characterized by rapid dissolution, copious sudsing, excellent detergency, and which is substantially non-frosting in storage.

Further objects and advantages will appear as the specification proceeds.

Typical flow sheets for preparing the solid soap compositions of this invention are shown in FIGS. land 2 of the drawing. These flow sheets are subsequently discussed in detail.

This invention is based in part on the discovery that a soap base composed substantially exclusively of potassium salts of fatty acids containing either 16 or 18 carbon atoms can be mixed with a minor proportion of an anionic-type synthetic detergent to produce a solid soap composition of exceptional quality for use in salt or hard water, and that the soap compositions thus produced are comparable in all respects to soaps containing a high percentage in the soap base of salts of fatty acids containing either 12 or 14 carbon atoms, and superior to such soaps in a number of respects.

Potassium soaps are commonly referred to as soft soaps, because of their great afiinity for water, and because they are prepared and marketed in the form of liquid or paste soap products, rather than in the form of solid soaps. For example, liquid soaps for use in dispensers are usually made from coconut oil using caustic potash saponification. Soaps called green soaps are paste products made with soft oils or fatty acids and 100% caustic potash saponification. Shaving creams usually contain substantial percentages of coconut oil and hard fats or fatty acids saponified with caustic potash. With the exception of soap flakes or chips which are intended for washing fine fabrics, solid soap products are not at present formulated with potash soaps. Even in the case of fine fabric flakes, only a minor proportion (10 to 30%) of potassium soaps are combined with the sodium soaps.

Apparently potassium base soaps have not been marketed in solid form because of their relative softness and hygroscopic nature. It has recently been discovered that these defects could be overcome by reducing the moisture content in the solid soaps to a critically low value. This invention is described and claimed in co-pending application United States Serial No. 268,114, filed January 24, 1952, now Patent No. 2,738,335. During the experimental work leading to the present invention, it was discovered that the moisture content in the solid soap composition employing a potassium soap base could be considerably higher while still producing a satisfactory product from the standpoint of hardness and hygroscopicity when the soap composition contains synthetic detergent in the amount of the present invention. The use of relatively high titer fatty acid stock for preparing the soap compositions of this invention is also important to produce a soap of the desired physical properties, as will subsequently be discussed in detail.

The soap base for use in preparing the solid soap composition of the present invention can be composed substantially entirely of potassium salts of fatty acids containing either 16 or 18 carbon atoms, or a mixture of the two. The fatty acids can be either saturated or unsatu rated. Preferably, the soap base ,is composed entirely of the potassium salts of tallow fatty acids. The potassium soap used in composition of this invention can be prepared by either saponification of the triglycerides of the fatty acids or by neutralization of the free fatty acids. If the triglycerides are saponified with potassium hydroxide, it is not necessary to remove the glycerine, although this is preferred since the glycerine is a valuable by-product. Preferably, the triglycerides are first split and the free fatty acids are recovered. The free fatty acids are then reacted with potassium hydroxide to produce the desired potassium salts of the fattyacids.

For the purpose of producing soap in bar form from the soap composition of this invention, it has been found desirable to employ fatty raw material having a relatively 'high titer. The use of high titer fatty acid stock increases the firmness of the finished bar, and decreases the hygroscopic tendency of the potassium soap. Titer is a standard test for fats and oils in which the sample is completely saponified, and the solidifying point (or titer) of the resulting separated and washed fatty acids is determined. Preferably, the fatty acid stock for use in preparing the potassium soap base should have a titer of between about 40 to 50 C. The optimum range is from about 43 to 47 C. The titer of tallow or other fat can be increased by hydrogenation, if its titer is lower than desirable. Also, a mixture having the desired titer can be prepared by the mixing ofa low titer stock with a high titer stock.

A wide variety of synthetic detergents can be satisfactorily employed in the solid soap composition of this invention. The general class of synthetic detergents suitable for use in the present soap composition can be defined as an anionic-type synthetic detergent having pronounced detergent power and including in its molecular structure an alkyl radical containing from 6 to 18 carbon atoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid esterradicals. In addition, the anionic-type synthetic detergent for use in this invention is preferably normally solid, although paste or liquid type detergents can be employed.

The main types of detergents falling Within the above class are: (l) the alkyl aryl sulfonates; (2) the alkyl sulfates; (3) the sulfonated fatty acid amides; and (4) the sulfonated monoglycerides.

'The alkyl aryl sulfonates are preferred, but the other types of detergents listed can be employed. Either the it sodium or potassium salts of the anionic-type detergents can "be used. Specific examples of alkyl aryl sulfonates which can be employedare sodium or potassium dodecyl benzene sulfonate, sodium or'potassium octadecylbenzene sulfonate, and sodium or potassium octyl naphthalene sulfonate. Specific examples of the alkyl sulfates which can:be employed are the sodium and potassium salts of L dodecyl, hexadecyl-and octadecyl sulfates. Speeificexamples of suitable sulfonated fatty acid amides include the sodium and potassium salts of sulfonated amides of higher fatty acids such as the sodium or potassium salt of the oleic acid amide of methyl taurine. The sulfonated monoglycerides which can be employed are preferably either sodium or potassium salts of higher fatty acids of monoesters or lower molecular weight hydroxy alkyl sulfonates such as the oleic acid ester of the sodium salt of isethionic acid and the monococonut oil fatty acid ester of 1,2 hydroxy propane 3 sodium sulfonate. It will be understood that the specific synthetic detergents mentioned are only illustrative of those falling within the scope of this invention, and that other equivalent detergents can be substituted therefor.

It has been found that the ratio of potassium soap to synthetic detergent is important for obtaining a solid soap product having the desired characteristics. On a dry basis at least .2 part by weight of active detergent should be used for each part by weight of potassium soap. About the maximum ratio which can be employed is 1 part by weight of active detergent to 1 part by weight of potassium soap. Preferably, the weight ratio of active detergent to potassium soap is between about .3 to .7 part of detergent to each part of potassium soap. The optimum range appears to be from about .4 to .5 part detergent to each part of potassium soap.

It is desirable for the solid soap composition to contain at least 6 but not substantially over 26% by weight of water on the basis of the total weight of the composition. Other ingredients can be incorporated in the composition to improve the properties thereof; for example, a soil redeposition retarder such as carboxymethyl cellulose (C.M.C.). About 1% of C.M.C. on the basis of the total weight of the composition is usually sufficient for this purpose. It may also be desirable to add from 1 to 2% by weight based on the total weight of the composition of sodium chloride to control the stiffness of the mixture. The use of sodium chloride is particularly important when the solid soap composition is to be formed into bars by framing. Other relatively inert ingredients such as sodium sulfate can be included without harmful effect. A number of synthetic detergents such as the alkyl aryl sulphonates, contain sodium sulfate in addition to the active detergent in their commercially available form. Such detergents can be incorporated directly in the soap composition. In fact, in order to balance the formula while permitting the addition of more or less sodium chloride to regulate the stiffness of the mixture it is desirable to have an additional ingredient of a relatively inert nature such as sodium sulfate which can be varied to correspond with the increase or decrease in the amount of sodium chloride added. Starch can also be incorporated in the composition if desired. Other builders, fillers, etc., can be employed.

.It has also been found that the proportion by weight of potassium soap and synthetic detergent in the overall composition is of importance. Preferably, the solidsoap composition should contain from 30 to 60% by weight of potassium soap, and from 20 to 30% by weight of synthetic detergent.

The same equipment now used for preparing solid soap in the form of bars, chips, granules, etc., can be employed forpreparing the solid soap composition of this invention. The How sheets in the accompanying drawing illustrate the preparation of bars from the solid soap composition of this invention. FIG. 1 shows the preparation of bars of high moisture content by framing, while FIG. 2 shows the preparation of bars of low moisture content by milling and plodding. Other procedures can be employed.

Referring first to FIG. 1 there is shown a crutcher 11, whichis a special type of steam-jacketed agitator used in soap making. The tallow fatty acids, potassium hydrpxide, synthetic detergent, and other additives (if employed), are charged to crutcher 11 where they are stirred and heated to bring about the neutralization reaction between the fatty acids and the potassium hydroxide. Upon the completion of the chemical reaction in the crutcher, and the thorough mixing of the ingredients therein, the molten soap composition is flowed into frames 12, and allowed to cool and set up for several days. The sides of the frames are then removed, and the soap is put through a slabber and cut into bars of approximately the right size. These operations are illustrated at 13 in the flow sheet of FIG. 1. The rough bars are then dried at 14 or passed directly to a press at 15 where they are stamped in the usual manner to produce the finished bars which are wrapped at 16.

In FIG. 2 there is shown a crutcher 101 of the same type as crutcher 11 in FIG. 1. Into crutcher 101 are charged the free tallow fatty acids and potassium hydroxide, which are stirred and heated until the neutralization reaction is complete. The molten soap is then flowed onto a chilled roll 102, which is generally associated with a small roll (not shown) which together spreads and chills the soap into a large flat sheet about the large roll. This sheet of soap is then cut into ribbons by a series of metal protrusions on the doctor knife 103. These ribbons are removed by the doctor knife and conveyed to a dryer 104, in which the moisture content of the soap is reduced to the desired value for the subsequent operations in the finished product.

After the ribbons of soap are dried to the desired moisture content, they are passed to an amalgamator 105, which is a specialized type of mixer employed in soap manufacturing. The synthetic detergent and other additives (if employed) are charged to amalgamator 105 and thoroughly blended with the potassium soap to produce a homogeneous mixture. Upon leaving the amalgamator the soap compositon is passed through a series of devices which further knead and mix the soap composition. These may take the form of squeeze rolls 106 and screw conveyor or plodder 107. Upon leaving the upper end of screw conveyor 107, the soap composition is extruded through a die member 109. The extruded soap composition is then further processed to produce the finished bars by cutting at 110, pressing at 111, and wrapping at 112.

In order to better illustrate the invention, it is desired to set out the following illustrative examples.

Example I Following the procedure illustrated in the flow sheet of FIG. 1, 385 lbs. of hydrogenated tallow fatty acids having a titer of 45 C. were charged to a crutcher together with 157 lbs. of 50 B. potash lye (51% solids). The other ingredients charged to the crutcher were as follows:

306 lbs. of a commercial dodecyl benzene sodium sulfonate detergent (85%, active synthetic);

7 lbs. of sodium sulfate;

2 lbs. of sodium chloride;

10 lbs. of carboxy-methyl cellulose (100% active basis);

and

133 lbs of water.

The above ingredients were crutched together until the reaction between the potassium hydroxide and the free fatty acids was complete. The mixture was dropped into frames, and allowed'to cool and set up for several days. The sides of the frames were then removed and the frame soap was put through a slabber and cut into bars of approximately the desired size. The rough-cut bars were then stamped in a press in the usual manner to give the finished bar. The finished bars were found to beof the following composition: moisture, 24%; potassium hydroxide, 0.06%; sodium sulfate, 4.87%; sodium chloride, 0.20%; carboxy-methyl cellulose, 1%; active synthetic detergent, 26%; and potassium soap, 43.87%.

The synthetic detergent employed was commercially prepared dodecyl benzenesodium sulfonate in the form of flakes. It was 85% active synthetic detergent and contained sodium sulfate as an inactive component.

Example II Milled and plodded bars were prepared as follows: The potassuim soap was made in a crutcher and processed in the usual manner to produce potassium soap flakes by 100% potassium hydroxide saponification of tallow fatty acids having a titer of 45 C. 530 lbs. of these potassium soap flakes were charged to an amalgamator together with 306 lbs. of a commercial alkyl aryl sulfonate detergent active). In addition, 114 lbs. of cornstarch, 10 lbs. of carboxy-methyl cellulose active), and 40 lbs. of water were added to the mix in the amalgamator. These ingredients were thoroughly mixed to produce a relatively homogeneous mixture, which was then put through a roller mill and finishing plodder. The mill -plodded composition was then cut to size and stamped to produce the finished bars in the usual manner. This process is shown in FIG. 2 of the drawmg.

The bars thus produced were found to have the following composition: moisture, 6.83%; potassium hydroxide, 0.04%; sodium sulfate, 4.13%; starch, 10%; carboxy-methyl cellulose, 1%; active synthetic detergent, 26%; and potassium soap, 52%.

The synthetic detergent employed was a commercially prepared mixture of dodecyl benzene sodium. sulfonate and nonyl benzene sodium sulfonate. It had an average molecular Weight of approximately 300. It is considered a medium molecular weight alkyl aryl sulfonate and was obtained in the form of flakes. The inert component was sodium sulfate.

Example III A solid soap composition in bar form and of low moisture content was produced by a variation of the procedure set out in Example II. 283 lbs. of tallow fatty of around 160 F. The resulting slurry containing around 29.7% water was passed to a drier where it was formed into medium sized chips at a drier temperature of around 150 F. The dried chips were then hashed and formed into pellets, which were introduced into a plodder from which they were extruded and formed into bars.

The bars thus produced were found to have the following composition: moisture, 8%; potassium soap, 42.19%; active synthetic detergent, 25%; starch, 15%;

"sodium tripolyphosphate, 5%; inorganic salts, 3.81%;

and carboxy-methyl cellulose, 1%.

The synthetic detergents employed were (1) 315 pounds of a 35% aqueous slurry of dodecyl benzene sodium sulfonate and (2) 108 pounds of a commercially prepared, 85% active synthetic, sodium alkyl aryl sulfonate detergent.

Example IV The bars produced in Examples I and II were tested to determine their eificiency in hard water and in sea water. The hard water employed had a hardness of about partsper million. Since actual sea water was not available, a synthetic sea water was prepared by dissolving the following salts in 400 ml. of water: 11 gms. magnesium-chloride; 1.6 gins. calcium chloride; 4.0 grns. sodium sulfate; and25 =gms. sodium chloride. The volume was then-diluted to 100 ml. to produce a synthetic sea water having a .total hardness as calcium carbonate (calculated) of 6500 parts per million.

For purposes of comparison, bars of similarcomposition, except thatthey contained coconut oil sodasoap in stead of potassium tallow soap, were also tested. The first test to which the soap compositions were subjected was the standard detergency test performed in a Launder- Ometer. At a concentration of about 3% of the soap compositions, the bars of Examples I and II were found to remove at least 10% more soil than the soap composition containing the coconut oil soda soap instead of the potassium tallow soap. The soap compositions were also subjected to standard Whiteness Retention tests in which the loss of whiteness of standard cotton fabric on repeated washing tests with the soap compositions was determined. At a concentration in hard water of about .3% the Whiteness Loss in Hunter Units was about twice as great for the soap composition containing the coconut oil soda soap, as it was for the soaps of Examples I and II. At a concentration of about .6% in sea water, the Whiteness Loss in Hunter Units for the soap composition containing the coconut oil soda soap was over 2% times as great as that for the soap compositions of Examples I and II.

The soap compositions of Examples I and II were also compared with a soap composition composed wholly of soda coconut oil soap. At about a .3% concentration of the soap compositions in hard water, it was found that the soap compositions of Example I and II removed about 33% more soil in a Launder-Ometer detergency test than the soda coconut oil soap.

In general, the performance of the solid soap compositions of this invention when used in sea water (or hard water) is excellent. The soap composition dissolves rapidly even at low temperatures, displays excellent detergency, and sudses rapidly with a minimum of mechanical action. There is strong indication of a marked synergistic cooperation between the synthetic detergent and the potassium soap. One fact in support of this is that the combination of a potassium soap of fatty acids having 16 and 18 carbon atoms with one of the preferred class of synthetic detergents was found to produce suds more rapidly than pure sodium coconut oil soap.

It was also found that the cooperation between the potassium soap and the synthetic detergent resulted in another unexpected advantage. Solid soap compositions in bar form which had been prepared from sodium tallow soap or sodium coconut oil soap in admixture with a synthetic detergent had been found to develop frost on the outer surface of the bars which resulted in an undesirable appearance. It is believed that this frosting is due to the migration of inorganic salts such as sodium chloride and sodium sulfate to the surface of the bars. For some reason which is not fully understood, however, solid soap compositions produced in accordance with this invention from potassium soap and synthetic detergent do not display any tendency to develop frost on their outer surfaces, even though they contain substantial amounts of inorganic salts. It can be readily understood that this is a considerable advantage from a commercial standpoint. As indicated above, it is frequently desirable to have solid soap compositions of the type with which this invention is concerned contain substantial amounts of inorganic salts such as sodium sulfate, sodium chloride, etc. For example, these soap compositions usually contain at least 1 to 5% by Weight of sodium sulfate, or a mixture of sodium chloj ride and sodium sulfate. When the synthetic detergent employed is an alkyl aryl sulfonate as preferred, as much as .1 to .15 parts by weight of sodium sulfate per part of 7 active detergent is usually incorporated in the final composition. because the commercially available alkyl aryl sulfonates generally contain up to 15% or more sodium sulfate.

I While in the foregoing specification specific details of this invention have been set forth for purpose of illustration, it will be apparent to those skilled in the art that many of these details can be varied widely without departing from the spirit of the invention.

" We claim: Y 1; 'A solid soap composition, comprising a mixture of substantially entirely potassium soap of fatty acids containing from 16 to 18 carbon atoms with an anionic synthetic detergent having pronounced detergent power and including in its molecular structure an alkyl radical containing from 6 to 18 carbon atoms and a radical selected from the group consisting of sulfuric acid and sulfonic acid ester radicals, said soap composition containing from .2 to 1 parts by weight of said synthetic detergent to each part of said potassium soap, the fatty acid stock used to prepare said potassium soap having a titer of from 40 to C.

2. A solid soap composition in bar form, comprising a mixture of substantially entirely potassium soap of fatty acids containing from 16 to 18 carbon atoms with from .2 to 1 parts by Weight of an alkyl sulfate detergent to each part of said potassium soap, the fatty acid stock used to prepare said potassium soap having a titer between about 40 to 50 C.

3. A solid soap composition in bar form, comprising a mixture of substantially entirely potassium soap of fatty acids containing from 16 to 18 carbon atoms with from .2 to 1 parts by weight of an alkyl aryl sulfonate detergent to each part by weight of said potassium soap, the fatty acid stock used to prepare said potassium soap having a titer of from 40 to 50 C.

4. A solid soap composition in bar form, comprising a mixture of substantially entirely potassium soap of fatty acids containing from 16 to 18 carbon atoms with from .3 to .7 parts by weight of an alkyl aryl sulfonate detergent to each part by weight of said potassium soap, the fatty acid stock used to prepare said potassium soap having a titer of from 40 to 50 C.

5. A solid soap composition in bar form, comprising a mixture of substantially entirely potassium soap of fatty acids containing from 16 to 18 carbon atoms with from .3 to .7 parts by weight of an alkyl aryl sulfonate detergent to each part by weight of said potassium soap, the fatty acid stock used to prepare said soap having a titer between about 43 to 47 C.

6. A solid soap composition in bar form, comprising a mixture of potassium tallow soap with a minor proportion by weight based on said potassium soap of an alkyl aryl sulfonate detergent, the tallow stock used to prepare said tallow soap having a titer of from 40 to 50 C., said potassium soap forming from 30 to by weight of said solid soap composition and said alkyl aryl sulfonate detergent forming from 20 to 30% by weight of said solid soap composition, all of the soap in said composition consisting substantially entirely of said potassium tallow soap.

7. A solid soap composition in bar form, comprising a mixture of potassium tallow soap with from .3 to .7 parts by weight of an alkyl aryl sulfonate detergent to each part by weight of said potassium-soap, the tallow fatty acid stock used to prepare said soap having a titer of between about 40 to 50 0, all of the soap in said composition consisting substantially entirely of said potassium tallow soap.

8. A solid soap composition in bar form characterized by being substantially non-frosting during storage and use, comprising a mixture substantially entirely of potassium soap of fatty acids containing from 16 to 18 carbon atoms with a normally solid anionic synthetic detergent having pronounced detergent power and including in its molecular structure and alkyl radical having from 6 to 18 carbon atoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals, said soap composition containing from .2 to 1 part by weight of said synthetic detergent to each part of said potassium soap, said soap composition also containing from 1 to 5% by weight of at least one inorganic salt selected from the group consisting of sodium sulfate and sodium chloride, the fatty acid stock used to prepare said potassium soap having a titer of from 40 to 50 C.

acids containing from 16 to 18 carbon atoms with from References Cited in the file of this patent .2 to 1 parts by weight of an alkyl aryl sulfonate detergent to each part by weight of said potassium soap, said UNITED STATES PATENTS soap composition also containing from .1 to .15 parts by 1,906,484 Nuesslein May 2, 1933 weight of sodium sulfate per part of alkyl aryl sul fonate 5 2,390,295 Flett Dec. 4, 1945 detergent, the fatty acid stock used to prepare said soap 2,407,647 Badman Sept. 17, 1946 having a titer between about 43 to 47 C. 2,704,279 Heald Mar. 15, 1955 

1. A SOLID SOAP COMPOSITION, COMPRISING A MIXTURE OF SUBSTANTIALLY ENTIRELY POTASSIUM SOAP OF FATTY ACIDS CONTAINING FROM 16 TO 18 CARBON ATOMS WITH AN ANIONIC SYNTHETIC DETERGENT HAVING PRONOUNCED DETERGENT POWER AND INCLUDING IN ITS MOLECULAR STRUCTURE AN ALKYL RADICAL CONTAINING FROM 6 TO 18 CARBON ATOMS AND A RADICAL SELECTED FROM THE GROUP CONSISTING OF SULFURIC ACID AND SULFONIC ACID ESTER RADICALS, SAID SOAP COMPOSITION CONTAINING FROM .2 TO 1 PARTS BY WEIGHT OF SAID SYNTHETIC DETERGENT TO EACH PART OF SAID POTASSIUM SOAP, THE FATTY ACID STOCK USED TO PREPARE SAID POTASSIUM SOAP HAVING A TITER OF FROM 40 TO 50* C. 